double witching hour
noun[S]
STOCK MARKETukus(alsodouble witching)thefinalhouroftradeon afinancialmarketon thedaywhen two of threetypesofoptionorfuturesagreementsend:
Theexpiryof theSeptemberfuturesandoptionsmeanttraderswerebusydealingwith thedoublewitchinghour.
See also
the triple witching hour